1. Field of the Invention
The present invention relates to a printing apparatus and control method thereof.
2. Description of the Related Art
Along with the recent spread of networks in offices and the like, even printing apparatuses (for example, printer and copying machine) have a network connection function. In general, printing apparatuses, user terminals, and the like are connected to a network, and the printing apparatus is shared and used between users, departments, and the like. Printing apparatuses are arranged in accordance with the printing load, and the printing operation cost is calculated for each user and each department. There is a demand for an environment where the printing history can be managed in detail.
The printing apparatus needs to reduce its power consumption. To do this, the printing apparatus shifts to a low power consumption mode (to be referred to as a sleep state) unless it receives data from a host apparatus (for example, PC (Personal Computer)) for a predetermined time. Immediately when the printing apparatus receives data in the sleep state, it shifts to a printable state (to be referred to as a standby state).
Japanese Patent Laid-Open No. 08-324071 discloses a technique of analyzing information stored in a reception buffer and if information to restart the power supply to each unit of the main body is stored as a result of the analysis, restarting power supply. Further, Japanese Patent Laid-Open No. 08-324071 mentions even a technique of, when it is determined that information stored in the reception buffer has exceeded a predetermined amount, analyzing the information in the reception buffer, and if information to restart power supply to each unit of the main body is stored, restarting power supply.
In the technique disclosed in Japanese Patent Laid-Open No. 08-324071, data to be transmitted from the host apparatus to the printing apparatus contains print data and data which need not be printed. The data which need not be printed includes, for example, data about print settings and the like, data about the status of the printing apparatus, and a transmission request to obtain print information about management of the printing history.
When the printing apparatus receives data about print settings and the like, the print settings and the like need not be reflected in the printing apparatus immediately after reception, and suffice to be reflected in next printing execution. To the contrary, when the printing apparatus receives a transmission request from the host apparatus, it needs to respond to the host apparatus within a predetermined period. To respond to a status transmission request from the host apparatus, the printing apparatus obtains a status after the start of power supply to necessary functional blocks. To respond to a print information transmission request from the host apparatus, the printing apparatus obtains print information after the start of power supply to a storage unit which holds print information.
Thus, the technique disclosed in Japanese Patent Laid-Open No. 08-324071 significantly reduces power consumption effect when the printing apparatus receives data about print settings and the like which do not require the immediacy of power supply to a functional block. However, when the printing apparatus receives a status transmission request/print information transmission request which requires the immediacy of power supply, the power consumption reduction effect becomes low. Especially, print information requires detailed printing history management necessary in calculation of the printing operation cost and the like. Information needs to be held as much as possible. In an HDD-equipped printing apparatus, print information is generally stored in the HDD.
The HDD requires high power consumption in spin-up, and frequent repetition of supply and stop of power to the HDD further degrades the power consumption reduction effect. This problem becomes particularly serious in a printing apparatus which is shared and used between a plurality of host apparatuses.